Backrest armrest linkage assembly and folding chair frame

ABSTRACT

A backrest armrest linkage assembly and folding chair frame; the backrest armrest linkage assembly includes a backrest bar and a armrest bar, wherein the middle section of the backrest bar is hinged on the rear support shaft behind the chair, and the lower end is constrained in the guide sleeve. The front section of the armrest bar is positioned on the front support shaft in front of the chair through the chute seat, and the rear end section is hinged to the lower section of the backrest bar, which can draw and restrain the swing angle of the backrest bar, and thus constitute a folding chair frame with adjustable backrest.

BACKGROUND OF THE INVENTION Field of the Invention

The invention is to folding chairs and particularly relates to a backrest armrest linkage assembly, and a backrest adjustable folding chair frame composed of such linkage assembly.

Technical Background

There are two main types of backrest adjustment in existing adjustable folding chairs. One type completes the positioning of the backrest angle change through an independent mechanism, and the other type forms a linkage between the backrest and the armrest such that the armrest can control and position the angle of the backrest. Obviously, the latter is more advantageous and has become the current design mainstream.

For example, Chinese Application CN201220165283.1 shows a support and adjustment structure for a backrest tube of a folding chair, including a backrest tube, a rear cross tube, a backrest auxiliary tube, and a backrest connector. Both ends of the backrest auxiliary tube are connected to the backrest tube through two upper and lower backrest connectors, thus forming a closed rectangular space. One end of the rear cross tube is movably connected to the rear end of the seat frame tube of the folding chair, and the other end slides up and down in the rectangular space formed above along the backrest tube through the slider. One end of the armrest tube is positioned at the upper-rear end of the front support tube by means of a sliding groove and is hinged with the backrest tube. The lower end of the backrest tube is hinged to the seat cushion tube. The inclination angle of the backrest tube is adjusted by moving the armrest tube back and forth. Since the upper end of the rear cross tube plays a key supporting role, and the backrest tube are slidingly connected with a complex structure, the stability is limited, and it is difficult to slide smoothly during adjustments.

Therefore, providing a linkage assembly and a folding chair frame with stable support and smooth adjustment has become a research object of the present invention.

SUMMARY OF THE INVENTION

A purpose of the present invention is to provide a backrest armrest linkage assembly in which the middle section of the backrest bar is hinged to the rear support section, and the lower section is pulled by the armrest to form an adjustable support structure, and a backrest adjustable folding chair frame is composed of the backrest armrest linkage assembly.

A technical plan of this invention was completed in one or more of the following manners:

A backrest armrest linkage assembly comprises a backrest bar and an armrest bar, with the following characteristics: The middle section of the backrest bar is hinged on the rear support shaft behind the chair, and the inclination angle can be adjusted by swinging around the rear support shaft. The front section of the armrest bar is positioned on the front support shaft in front of the chair through the chute seat. The rear end is hinged to the lower section of the backrest bar, which can draw and constrain the swing angle of the backrest bar. The lower end of the backrest bar is constrained in a guide sleeve, which is riveted to the chair and has a constant relationship with the rear pivot.

The chute seat is riveted below the armrest bar, and the front end of the transversely penetrating chute has a clip slot that faces upwards. The front support shaft in front of the chair transversely passes through the chute so as to slide relative to each other. It can be constrained when sliding to the stopper opening to form a positioning structure.

A hinge seat is riveted at the hinged joint between the backrest bar and the armrest bar, and the end of the armrest bar is hinged on the protruding hinge seat.

The guide sleeve has a long groove structure. When the backrest bar is at the maximum inclination angle, the lower end section abuts the front section of the guide sleeve, and the width of the long groove allows the lower end of the backrest bar to swing freely in the front and rear directions.

A type of folding chair frame is provided which includes brackets arranged correspondingly or symmetrically on both sides, a front cross-bar group and a rear cross-bar group associated with the brackets on both sides, and the backrest armrest linkage assembly. The bracket includes a front support bar, a rear support bar and a seat cushion bar. The front and rear support bars are hinged to form a herringbone support. The seat cushion bar is horizontally and correspondingly hinged on the front support bar and slidably positioned on the rear support bar.

An upright support bar is hinged at the front of the seat cushion bar. The upper end of the upright support bar is provided with a front support shaft, which slides through the chute seat below the armrest bar. The lower end is hinged with a front sliding sleeve, which is sleeved on the front support bar by means of the front sliding sleeve. The middle section of the backrest bar is hinged on the rear support shaft at the upper end of the front support bar, and the guide sleeve is also riveted to the front support bar to maintain a constant relationship with the rear support shaft.

The front support bar is hinged with the rear support bar and then extends upward for a section. The seat cushion bar is slidably positioned on the rear support bar by means of the rear sliding sleeve and extends backwards for a section at the hinged joint of the rear sliding sleeve. The upper and lower ends of the rear crossbar group are correspondingly hinged to the end of the extension section of the front support bar and the end of the extension section of the seat cushion bar.

The lower part of the front support bar is provided with a front limit ring, and the front limit ring is hinged on the same hinge point where the lower end of the front cross bar group is hinged with the front support bar. The upper end of the front cross bar group is hinged on the same hinge point of the upright support bar and the seat cushion bar.

The chute seat is also provided with longitudinal grooves. The upper end of the upright support bar can be inserted into it, and the two ends of the front support shaft fixed at the end correspond to the sliding grooves on the left and right sides.

The invention has an ingenious conception, where the backrest and the armrest are linked, and the backrest angle can be adjusted and restrained. When applied to the folding chair frame, there are few supporting nodes, and it can follow the opening and folding process of the folding chair frame. The operation is smooth and convenient, and the adjustment and restraint of the two extreme states of upright and inclined backrest can be realized. It has the characteristics of a simple structure and can meet the most basic backrest adjustment requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of the backrest armrest linkage assembly.

FIG. 2 shows a schematic exploded diagram of the folding chair frame.

FIG. 3 shows a schematic diagram of the folding chair frame.

FIG. 4 shows a schematic diagram of the folding chair frame in a folded state.

FIG. 5 shows a schematic diagram of the folding seat frame backrest in an upright state.

FIG. 6 shows a schematic diagram of the folding chair frame backrest in a resting state.

Similar reference characters denote corresponding features consistently throughout the attached drawings. Namely, in the drawings the following reference numbers refer to the following part:

   1—Backrest bar  11—Hinged seat  12—Armrest bar  21—Chute seat 211—Chute 212—Clip slot 213—Longitudinal slot  3—Guide sleeve  4—Front crossbar group  5—Rear cross bar group  6—Front support bar  61—Front limit ring  7—Rear support bar  71—Rear limit ring  8—Seat cushion bar  81—Rear sliding sleeve  9—Upright support bar  91—Front sliding sleeve  A—Rear support shaft  B—Front support shaft  C—Riveting point

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to FIGS. 1 and 2 , a backrest armrest linkage assembly is shown that includes a backrest bar 1, a armrest bar 2 and a guide sleeve 3. The middle section of the backrest bar 1 is hinged on the rear support shaft A behind the chair and can swing around the rear support shaft A to adjust the inclination angle. The backrest bar 1 provides support and positioning of the backrest fabric material or backrest sheet to form a complete backrest to support the human body.

The front section of the armrest bar 2 is positioned on the front support shaft B in front of the chair through the chute seat 21, and the rear end section is hinged to the lower section of the backrest bar 1, which can draw and constrain the swing angle of the backrest bar 1. The lower end of the backrest bar 1 is constrained in a guide sleeve 3, which is riveted to the chair and has a constant relationship with the rear pivot A. More specifically, the guide sleeve 3 is riveted to the riveting point C of the chair and the position of the rear pivot A is constant, or it can be understood as the same chair structural part. The guide sleeve 3 is a long groove structure. When the backrest bar 1 is at a maximum inclination angle, the lower end section is in contact with the front end section of the guide sleeve 3. The width of the long slot allows the lower end of the backrest bar 1 to swing freely in the front and rear directions and keeps the backrest bar 1 always in the adjustment plane. Namely, in the plane formed with the armrest bar 2, the backrest bar 1 and the armrest bar 2 cannot sway left and right, playing a key role in its stability. The use of the guide sleeve 3 can also act as a travel limit for the adjustment of the backrest bar 1. The backrest bar 1 is in the upright and inclined limit position, and the lower end corresponds to the rear end and front end of the guide sleeve 3, and especially the front end also acts as a lever balancing force to increase the rigidity of the backrest.

Furthermore, the chute seat 21 is riveted under the armrest bar 2, and the front end of the transversely penetrating chute 211 is provided with a clip slot 212 facing upwards. The front support shaft B in front of the chair transversely passes through the chute 211 and can slide relatively and can be constrained when sliding to the clip slot 212. In other words, when the armrest bar 2 moves back and forth, the clip slot 212 slides to the front support shaft B, and the armrest bar 2 falls naturally and is stopped, forming a positioning structure corresponding to the reliable positioning of the backrest bar 1 in its upright state.

Furthermore, a hinged seat 11 is riveted at the hinged joint between the backrest bar 1 and the armrest bar 2, and the end of the armrest bar 2 is hinged on the protruding hinged seat 11. This allows the backrest bar 1 and the armrest bar 2 to be in an overlapping plane and also provides space when the armrest bar 2 is folded.

It can be seen from the specific example in FIG. 2 that the backrest armrest linkage assembly can be used not only with a folding chair frame, but also with a fixed chair, so that the backrest can be adjusted. In addition, in this design, only one clip slot 212 is provided on the chute seat 21 to realize the positioning of the two extreme design inclination angles of the backrest, thereby simplifying the positioning of unnecessary transition angles.

Using the backrest armrest linkage assembly, an example of the designed folding chair frame is as follows:

Referring to FIGS. 2-6 , a folding chair frame includes brackets correspondingly or symmetrically arranged on both sides, a front cross-bar group 4 and a rear cross-bar group 5 associated with the brackets on both sides, and the backrest armrest linkage assembly.

The bracket includes a front support bar 6, a rear support bar 7 and a seat cushion bar 8. The front and rear support bars 6 and 7 hinge to form a herringbone support. The seat cushion bar 8 is horizontally and correspondingly hinged on the front support bar 6 and slidably positioned on the support bar 7, forming a triangularly related and foldable bracket. The brackets on the left and right sides are connected by the front and rear cross bar groups 4 and 5 to form the whole folding chair frame. More specifically, the middle section of the seat cushion bar 8 is directly hinged on the front support bar 6, and the rear section is hinged with a rear sliding sleeve 81, which is sleeved on the rear support bar 7 by means of the rear sliding sleeve 81. A rear limit ring 71 is correspondingly riveted on the rear support bar 7 to block the rear sliding sleeve 81 from ascending and receiving force.

The front part of the seat cushion bar 8 is hinged to an upright support bar 9, and the upper end of the upright support bar 9 is provided with a front support shaft B. It slides through the chute seat 21 below the armrest bar 2, and the lower end is hinged to a front sliding sleeve 91, which is sleeved on the front support bar 6 by means of the front sliding sleeve 91. The upright support bar 9 not only forms the support for the armrest 2, but also directly guides the front section of the cushion bar 8 to the front support bar 6. Thus, a front limit ring 61 is riveted on the front support bar 6 to provide a resistive force for the front sliding sleeve 91 to be opened in place. The front limit ring 61 is hinged on the same hinge point where the lower end of the front cross bar group 4 is hinged with the front support bar 6, which saves the assembly process. The upper end of the front cross bar group 4 is also hinged on the same hinge point of the upright support bar 9 and the seat cushion bar.

The middle section of the backrest bar 1 is hinged on the rear support shaft A at the upper end of the front support bar 6, and the guide sleeve 3 is also riveted to the front support bar 6 to maintain a constant relationship with the rear support shaft A.

Furthermore, the front support bar 6 is hinged with the rear support bar 7 and then extends upwardly for a section. The seat cushion bar 8 is slidably positioned on the rear support bar 7 by means of the rear sliding sleeve 81 and extends backwards for a section at the hinged joint of the rear sliding sleeve 81. The upper and lower ends of the rear crossbar group 6 are correspondingly hinged to the end of the extension section of the front support bar 6 and the end of the extension section of the seat cushion bar 8 to provide space after folding.

Furthermore, the chute seat 21 is also provided with longitudinal grooves 213. The upper end of the upright support bar 9 can be inserted into it, and the two ends of the front support shaft B fixed at the end correspond to the sliding grooves 211 on the left and right sides, so as to centrally support the armrest bar 2.

The upright state and the resting state of the backrest mentioned above are only relatively speaking, and the images represent the two states of sitting and leaning. The rear pivot A, the front pivot B and the riveting point C are all rivet hinge points, which are the same as the riveting structures of other hinge points. 

We claim:
 1. A backrest armrest linkage assembly comprising a backrest bar and a armrest bar, the middle section of the backrest bar is hinged on the rear support shaft behind the chair, and the inclination angle can be adjusted by swinging around the rear support shaft; the front section of the armrest bar is positioned on the front support shaft in front of the chair through the chute seat, and the rear end is hinged to the lower section of the backrest bar, which can draw and constrain the swing angle of the backrest bar; and the lower end of the backrest bar is constrained in a guide sleeve, which is riveted to the chair and has a constant relationship with the rear pivot.
 2. A backrest armrest linkage assembly according to claim 1, wherein the chute seat is riveted below the armrest bar, and the front end of the transversely penetrating chute has a clip slot that faces upward; and the front support shaft in front of the chair transversely passes through the chute, and can slide relative to each other. It can be constrained when sliding to the stopper opening to form a positioning structure.
 3. A backrest armrest linkage assembly according to claim 1, wherein a hinge seat is riveted at the hinged joint between the backrest bar and the armrest bar, and the end of the armrest bar is hinged on the protruding hinge seat.
 4. A backrest armrest linkage assembly according to claim 1, wherein the guide sleeve has a long groove structure; whereby when the backrest bar is at the maximum inclination angle, the lower end section abuts the front section of the guide sleeve, and the width of the long groove allows the lower end of the backrest bar to swing freely in the front and rear directions.
 5. A folding chair frame, including brackets arranged correspondingly or symmetrically on both sides, a front cross-bar group and a rear cross-bar group associated with the brackets on both sides, and any backrest armrest linkage assembly, comprising: the bracket includes a front support bar, a rear support bar and a seat cushion bar; the front and rear support bars are hinged to form a herringbone support the seat cushion bar is horizontally and correspondingly hinged on the front support bar and slidably positioned on the rear support bar, an upright support bar is hinged at the front of the seat cushion bar, the upper end of the upright support bar is provided with a front support shaft, which slides through the chute seat below the armrest bar, the lower end is hinged with a front sliding sleeve, which is sleeved on the front support bar by means of the front sliding sleeve; and the middle section of the backrest bar is hinged on the rear support shaft at the upper end of the front support bar, and the guide sleeve is also riveted to the front support bar to maintain a constant relationship with the rear support shaft.
 6. A folding chair frame according to claim 5, wherein the front support bar is hinged with the rear support bar and then extends upward for a section; the seat cushion bar is slidably positioned on the rear support bar by means of the rear sliding sleeve, and extends backward for a section at the hinged joint of the rear sliding sleeve; the upper and lower ends of the rear cross-bar group are correspondingly hinged to the end of the extension section of the front support bar and the end of the extension section of the seat cushion bar.
 7. A folding chair frame according to claim 5, wherein the lower part of the front support bar is provided with a front limit ring, and the front limit ring is hinged on the same hinge point where the lower end of the front cross bar group is hinged with the front support bar; and the upper end of the front cross bar group is hinged on the same hinge point of the upright support bar and the seat cushion bar.
 8. A folding chair frame according to claim 5, wherein the chute seat is also provided with longitudinal grooves; the upper end of the upright support bar can be inserted into it, and the two ends of the front support shaft fixed at the end correspond to the sliding grooves on the left and right sides. 